In the past, various support structures below screening media or screen cloths have been used in a wide variety of applications.
A common deck design, of the past, has used a fabricated I-beam cross-member that tapers down toward the ends. The ends were typically welded into a formed plate that makes the deck sides. The tapered ends of the fabricated I-beam allow use of shortened height deck sides, which is desireable. This design can be used with either side tension style decks or with urethane media style decks, depending on which way the I-beam cross-member is oriented.
Another common design has been to use a straight tube design. Such designs often are symmetrical, and can be used with either side tension style decks or with urethane media style decks. These designs have often been relatively inexpensive.
While these types of support structure systems may have many advantages in particular applications, they also have some drawbacks. For example, with the fabricated I-beam approach some challenges are presented. Firstly, fabricating a tapered I-beam is costly. Secondly, welding around the I-beam ends causes stress concentrations due to the non-continuous welds and due to the geometry of the I-beam cross section. These stress concentrations fatigue with the cyclic loading of the screen, causing cracks to develop and the screen deck can begin to fail. With the straight tube design, it often forces designers to scale upwardly the deck sides with deck width. Eventually, the deck sides become too tall to be feasible for use, especially if it is often necessary to transport the screens on public highways between job sites, where height restrictions will apply to all vehicles.
Consequently, there exists a need for improved methods and apparatuses for efficiently supporting a screen cloth in vibrating screen machines.